Telephone



NOV. 5', 1946. W, H, EDW RD Em v 24mm TELEPHONE Filed Nov. 25. 1942 2SheetsSheet 1 INVENTORS WH. EDWARDS M 5. RICHARDSON ATTORNEY NW, 5,1945, w. H. EDWARDS ETAL TELEPHONE Filed Nov. 25. 1942 2 Sheet-Sheet 2FIG. /0

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'MSR/CHARDSON TMNSMITTEP END WWWW AT RMEK Patented Nov. 5, 1946 UNITEDSTATES PATENT OFFICE William H. Edwards, Fort Monmouth, N. J and Max S.Richardson, Wickford, R. I., assignors to Bell Telephone Laboratories,Incorporated, New York, N. Y., a corporation of New York ApplicationNovember 25, 1942, Serial No. 466,842

4 Claims. 1

This invention relates to telephones and particularly to improvements inswitching and signaling arrangements for hand telephones having aplurality of telephone instruments, such as a transmitter and receiver,mounted upon a common handle.

An object of the invention is to secure an improvement in thesubscribers telephone set by producing a self-contained multipositionalhandset that can be readily placed in any convenient position by thesubscriber.

A further object of the invention is to simplify the design of thetelephone set by eliminating the usual switchhook mounting providedtherefor and assembling the component parts in a common handle, wherebythe handset handle provides a unitary structure for containing theessential elements thereof.

A further object of the invention is to provide a hand telephone whichshall be simple in construction, economical to manufacture and tomaintain in operation, and which shall require a minimum amount ofadjustment.

Another and related object of the invention is a telephone set includingin a unitary structure the transmitting and receiving instruments,visual and audible signaling devices, and switching means forcontrolling these component elements.

With the above objects in view, one embodiment of the inventiondiscloses a telephone substation comprising a hollow handle in which aremounted the essential elements such as a transmitter at one end, areceiver at the other end, and a discharge tube and mercury gravityswitch within the shank thereof. The handle may be disposed for itsnormal or non-talking state either in a horizontal or vertical position.When ringing current is impressed over the subscribers line, thedischarge tube breaks down to give a visual signal, and the receiver,being serially connected with the tube, emits an audible tone. Themanual operation of lifting the handle from its position of rest closesa mercury switch, which replaces the usual switch-hook contacts and inturn closes a talking circuit, thereby conditioning the device fortalking purposes and shunting the discharge tube.

Another embodiment of the invention disclose a similar hollow handlearrangement in which a dial is added for use in automatic switchingsystems.

Still another embodiment of the invention is disclosed in a hollowhandle arrangement in which the audible signaling means is improved byuse of a vacuum tube oscillator. H n

For a better understanding of the invention reference may be had to theaccompanying drawings in which:

Fig. 1 is a circuit diagram of the substation circuit;

Fig. 2 is a circuit diagram of an improved sub station circuit;

Fig. 3 is a view of the handset arranged for vertical suspension by itscord with the transmitter disposed at the top; I V

Fig. 4 is a view of the handset provided with a dial at the back of thereceiver and suspended from a fixed support; 7 v

Fig. 5 illustrates a handset having a partially flattened transmitterface for disposition face downwards on a table or desk;

Fig. 6 illustrates disposition of the handset upon its left side in theoperative or talking position; I

Fig. '7 illustrates disposition of the handset upon its right side inthe non-talking or disconnected position;

Fig. 8 is a circuit diagram of the substation circuit incorporating adial;

Fig. 9 is a circuit diagram of a vacuum tube oscillator for increasingthe audibility range of the receiver during signaling; and.

Fig. 10 shows a sectional view of a vertical suspended handset in whichthe discharge lamp and a mercury switch adapted for vertical mountingare brought out more clearly,

Referring to Fig. 1, a telephone substation line 20 is shown terminatedin a subscribers telephone handset 2| comprising a transmitter T, acurrent limiting resistance 22, glow discharge lamp 23, and a receiverR. shunting lamp 23 is a mercury positional switch 24, which comprises apair of contacts 26, 21 and a globule of mercury 28 hermetically sealedwithin a tube 29. Mercury switch 24 is so disposed Within the telephoneset that in the normally inoperative position thereof,

as hereinafter described, the switch is open while;

in the talking position the switch is closed. The position of switch 24,as shown in Figs. 1, 2, and 8, symbolically represents the disconnectedor nontalking position, contacts 26, 21 being separated from each otherand also from the mercury globule 28. Switch 24 replaces the switchhookcontacts Which are found in the usual telephone receiver and handsetmountings and which are subject to contact troubles because of exposureto atmospheric corrosion and dirt.

In response to the usual signaling current over 3 Subscriber linedischarge lamp 23 breaks down in an obvious circuit and glows as avisual indication, while receiver R, being serially connected with lamp23, emits a tone corresponding to the signaling frequency. Thesubscriber hearing the receiver tone and observing the lighted lamppicks up the receiver from its position 'of rest, as describedhereinafter, and thereupon shifts the position of mercury globule 28 sothat contacts 26, 21 of switch 24 become in contact therewith and becomeshort-circuited thereby. Interconnection of contacts 26, 2! shunts outresistance 22 and lamp 23 and renders effective a talking circuit, whichcan be traced from one side of line 20 through transmitter T,interconnected switch contacts 26, 21, receiver R, and thence back tothe other side of line 22. Upon restoral of the handset to its positionof rest the mercury globule 28 is disengaged from switch contacts 26,21,

which thereby being open-circuited, discharge lamp 23 is thereuponrendered effective for another call. For originating a call, theprocedure consists in picking up the handset whereupon contacts 26, 21are'interconnected by mercury globule 28 to close the customarysupervisory circuit at a central exchange. It is to be noted that theusually included telephone induction coil has also been eliminated fromthe telephone set, as talking tests have indicated that conversationsover such a simplified circuit have proven quite satisfactory. I

In some cases, particularly where it is desirable to increase theringing range of receiver R, a small capacitance is bridged thereacross.Fig. 2 shows a circuit arrangement suitable for such a purpose. Thisfigure is identical with that of Fig. 1 except that a small condenser 3|is connected to one side "of line 20 and to a junction point betweenresistance 22 and lamp 23. With the inclusion of condenser 3| in thecircuit signaling current impressed over line 20 will produce a moreaudible tone in receiver R.

Figs. 3, 4, 5, 6, and 7 illustrate various methods of supporting ahandset' Fig. 3 shows a handset 2| suspended vertically by its telephonecord 32 comprising the above-mentioned line conductors 2|]. Cord 32 maybe secured to a hook (not shown) or to any suitable support. It is to benoted that the transmitter T is at the top while the receiver R is atthe bottom of the suspended handset. While handset 2| is suspended inthis manner, mercury switch 24 (see Fig. 1) is so disposed within hollowshank 33 thereof that its contacts 26,21 are in an open-circuitcondition.

However, when transmitter T and receiver R are transposed for talkingpurposes by holding the instrument 2| in the customary manner, mercuryglobule 28 is moved into engagement with contacts 26, 21 to close thetalking circuit as hereinbefore described. This transposition takesplace when, responsive to ringing tone, the subscriber grasps the shank33 of handset 2| in a reverse manner, that is, with the back of his handfacing shank 33, as shown in Figs. 6 and 7. While win dow 34 is hereplaced in plate 38, it may as well be disposed in the shank 33.Furthermore, a window may be dispensed with by providing a hollowhandset made of translucent material such as Lucite.

In Fig. 4 is shown a unitary dial handset 2| also adapted for verticalsuspension. In this embodiment a dial 37 is mounted at the back of thereceiver R while the transmitter T is supported by a hook 38, which issecurely fastened to a supporting structure 39. The window 34 in thisinstance may be placed in the side of shank 33 for better visibility.

' In Fig. 5 is shown another embodiment of the invention in which aunitary handset 2| having a partially flattened transmitter face 4| isadapted for horizontal mounting on a desk 42 or any suit the observerand thumb at the bottom adjacent able flat surface. In the position ofrest as shown handset 2| has the transmitter T and receiver R facingdownward towards the surface of the desk. An inherent advantage in thisarrangement resides in the fact that ringing tone emitted by receiver Rcan be made to resonate by reflection from the surface of desk 4| and asa result produces a louder tone. Handset 2|, as illustrated, is in thenon-talking position and when removed from this position and placedeither in an upright position or on either side, is immediately switchedto a talking position by the above-described operation of mercury switch24.

In Figs. 6 and 7 handset 2| is shown with switch 24 disposed thereinalso for horizontal mounting on a table or desk the normal nontalkingposition. however, being on one of the side surfaces thereof and thetalking or closed circuit position being in an upright or horizontalposition on the opposite side thereof. Either side of handset 2| may bearranged for the normal non-talking position by proper disposition ofmercury switch 24 therein. As shown in Fig. 7, switch 24 has been sodisposed within hollow shank 33 that when the handset is laid on itsside with the transmitter T at the right and receiver R at the left(facing the observer) switch contacts 26, 2'! are disconnected from eachother. the globule of mercury 28 being at the lower side of tube 29.This position of handset 2| represents the normal non-talking conditionwhile the reverse position, as shown in Fig. 6, represents a talkingcircuit condition in which a subscriber for some reason or other may laythe instrument 2| down without disconnecting the connected partytherefrom. 'It is, of course, understood that the handset 2|, asillustrated in Figs. 6 and 7, will be in a talking circuit conditionwhen held in the customary talking position by a person. It is obviousthat reversal of switch 24 will correspondingly reverse the horizontaltalking and non-talking circuit positions illustrated in Figs. 6 and 7.Figs. 6 and '7 also show in more detail the arrangement of theassociated apparatus such as resistance 22, discharge lamp 23, mercuryswitch 24, and condenser 3| mounted within the hollow shank 33, coveringplate 36 being removed therefrom. The dot-dash lines superimposed uponlamp 23 represent the position of window 34 as mounted in Fig. 3.

In Fig. 8 is shown a schematic circuit, which is arranged for dialing.Here the arrangement is similar to that of Fig. 2 except that a dial 43has been added thereto, pulsing contacts 44 being serially interposedwithin the upper side of line conductors 20 and off-normal contacts 46shunting the telephone set during the dialing operation.

In Fig. 9 is shown a vacuum tube oscillator circuit for furtherincreasing the signaling range of the arrangement shown in Figs. 1 and2. This circuit, which is bridged to that of Fig. 1, is an improvementof that disclosed in W. H, Edwards Patent 1,860,458 of May 31, 1932. Theoperation is somewhat similar to that described in the above patentwherein discharge lamp 4'! responding to ringing current breaks down tosupply filament current for vacuum tube 48 through resistance t9, theplate circuit being in parallel with the discharge lamp-filamentcircuit. A receiver 5! included in the plate circuit gives an audiblesignal in response to the ringing current, said signal depending uponthe setting of the tuned grid oscillating circuit, as described in theabove-mentioned patent.

In Fig. is shown a mercury switch 52, which is particularly adapted fordisposition within a handset of the vertical mounting type, asillustrated in Figs. 3 and 4. Only the shank portion 33 of the handsetis shown, the transmitter being at the bottom and the receiver being atthe top, which is the reverse of that shown in Figs. 3 and 4. In otherwords, the partial view as shown is illustrative of the talking positionof the handset, wherein mercury switch 52 has its two terminals '53, 54short-circuited by a globule 56 of mercury. It is to be noted thatterminal 53 is spaced within a cylindrical metallic tube 5'! withouttouching any portion of the surface thereof while terminal 54 isattached to the outer surface of tube 51. In the normal position of restthe handset would be suspended with the transmitter at the top and thereceiver at the bottom and in this position mercury globule 55 would bedisposed in the tip portion 58 of tube 52 and thus disengaged fromterminals 53, 54. Upon grasping the handset, in the manner heretoforedescribed, mercury globule 5B is quickly attracted through the capillaryaction of tube 51 to short-circuit terminals 53, 54, therebyconditioning the handset for talking purposes.

While the features of this invention have been disclosed with referenceto the specific embodiments described herein, it is, of course,understood that various modifications may be made in the details ofconstruction without departing from the scope of this invention asdefined in the appended claims.

What is claimed is:

1. A telephone handset comprising a hollow housing of insulatingmaterial including an intermediate hand grip portion and also oppositeend portions for a telephone transmitter at one end and a telephonereceiver at the other end, a gas discharge tube in said hand gripportion, a circuit for serially interconnecting said transmitter,receiver, and tube, said circuit being responsive to ringing current,whereby said tube provides a visual indication of ringing current andthe receiver emits an audible signal, a capacitance bridging saidreceiver for increasing the audibility' of said receiver signal, and amercury switch disposed in said hand grip portion for shunting said tubeand conditioning said transmitter and receiver for talking purposes,said switch adapted to be open when the housing is in its normalposition of rest and adapted to be closed when the housing is removedfrom its position of rest.

2. A telephone handset comprising a hollow housing of insulatingmaterial including an intermediate hand grip portion and also oppositeend portions for a telephone transmitter at one end and a telephonereceiver at the other end, a first gas discharge tube in said hand gripportion, a circuit for serially interconnecting said transmitter,receiver, and tube, said circuit being responsive to ringing current,whereby said tube gives a visual indication and the receiver emits anaudible signal, means including an auxiliary gas discharge tube andoscillator for increasing the audibility of said signal, and a mercuryswitch disposed in said hand grip portion for shunting said first tubeand conditioning said transmitter and receiver for talking purposes,said switch comprising a pair of spaced contact terminals and a mercuryglobule assembled in a hermetically sealed tube, said terminals beingseparated from the mercury globule when the housing is in its normalposition of rest and being interconnected when the housing is removedfrom its position of rest.

3. A telephone handset comprising a housing of insulating material,including an intermediate hollow hand grip portion and opposite endportions, a telephone transmitter in one of said end portions, atelephone receiver in the other of said end portions, a resistance, aneon lamp and a mercury gravity switch in said hand grip portion, afirst and a second external telephone conductor connected to saidhandset, a first circuit extending in sequence from said firstconductor, through said transmitter, through said resistance, throughsaid neon lamp and through said receiver to said second conductor, saidcircuit for lighting said lamp and producing a ringing tone in saidreceiver as calling signals in'response to an alternating currentimpressed on said first circuit, and a second circuit extending from thepoint of junction between said transmitter and said resistance throughsaid switch to the point of junction between said lamp and saidreceiver, said switch being so disposed in said hand grip portion that,when said handset is in a first position with respect to a fixed plane,said first circuit is closed and said second circuit is open and, whensaid handset is in a second position with respect to said plane, saidsecond circuit is closed, so as to shunt said resistance and said lampand interconnect said transmitter and receiver directly through saidswitch to said first and said second conductors for talking purposes.

4. A telephone handset in accordance with claim 3 having a third circuitconsisting of a condenser, of small capacitance, connected directly fromthe point of junction between said resistance and said lamp and saidsecond conductor, to increase the intensity of said ringing toneproduced in said receiver.

WILLIAM H. EDWARDS. MAX S. RICHARDSON.

